1. Field of the Invention
The present invention generally relates to a power supply technology, in particular, to a power supply apparatus of a computer system and a method for controlling a power sequence thereof.
2. Description of Related Art
At present, the start-up process of a computer system is a very important link for a computer itself, and the computer system mentioned here is a computer system such as a notebook computer, a server, or a personal computer. No matter how perfect and strong the function design and calculation function of the computer system are, as long as the power sequence in the start-up process cannot be judged or processed perfectly, the computer system is unstable in operation and the occurrence probability of system shut-down without warning, restart-up, or even system damage is greatly increased.
Various components of the computer system require different voltage levels due to the difference in semiconductor processes and apparatuses, for example, a central processing unit (CPU), a chipset, and a dynamic random access memory (DRAM) have their respective required voltage levels. Therefore, power supply apparatuses of computer systems at present are all designed with power sequence control modules, and the power sequence control module is referred to as a power sequence state machine in some embodiments.
When a user presses a power button on the computer system to start it up, the control module starts power voltages successively, and only when the power voltage is stable and a component receiving the power voltage also operates normally, continues to start a power voltage of a lower level. Therefore, the control module starts all power voltages in turn (for example, in the order from high voltage to low voltage) until all the components in the computer system operate normally, so that the computer system enters from a start-up mode to a run-time mode and begins to start an operating system. In the run-time mode, the control module continuously monitors whether the components operate normally. As long as one of the components emits a power error signal, the existing control module usually performs a protection action such as forced shut-down or restart-up on the computer system immediately, so that the computer system is not damaged.
In this way, some components may immediately emit a power error signal due to transiently unstable voltage, even if the components return to normal right away later, and at this time, the computer system will be shut down or restarted up forcibly, so that the user's use of the computer system to access data is forcibly interrupted and the information being processed may be lost or damaged, even shortening the life cycle of the computer system.
The conventional solution is to add a de-bounce module constituted by a flip-flop at endpoints of the components where power error signals may be emitted, so as to eliminate the occurrence of transient power error signals. However, the de-bounce module only can eliminate signal change in a very short time, and when the duration of the power error signals emitted continuously exceeds the range that can be eliminated by the de-bounce module, the above deficiency still exists. In addition, the de-bounce module cannot set transient power errors for different components.
However, not every component has significant influence on the computer system after a transient power error occurs. In the currently used power supply technology, if the component in which an error occurs is a peripheral not affecting the entire operation of the system, the computer system is still shut down forcibly, thus incurring unnecessary loss to the user. Therefore, how to provide the computer system with a desirable power sequence control technology is a major problem to be solved for the computer system in the power supply technology.